I'm going to be in surgery in a few minutes, so I need to take a few bites of something to refuel.

I'm going to be in surgery in a little while, so I'm going to have to take a few sips of water to calm down.

NO!

Many patients have this question before having surgery:I thought you said you'd sleep through the surgery. Why can't you have something to eat or drink before you go to bed?

In fact, the experience of letting our patients "sleep through the procedure" is what we strive for. In fact, letting you "safely sleep through and wake up safely" is an advanced job. Advanced to the point that you do not breathe, we manage breathing; you do not feel the pain, can not be too deep or too shallow; your surgery center rhythm irregularities, blood pressure fluctuating high and low situation, all to regulate.

As you can see here, this "sleeping" comes with risks, some of which can be greatly reduced by perfect preoperative preparation.

The purpose of preoperative water fasting is to allow the stomach to empty completely, reduce gastric contents, and lower the acidity of gastric juice to prevent aspiration pneumonia caused by reflux of highly acidic gastric contents such as the lungs.

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So.Why might gastric contents regurgitate into the lungs during general anesthesia?

This is because during general anesthesia, the physiological functions that prevent reflux aspiration are suppressed and the factors that cause reflux are increased.

I. During general anesthesia, the lower esophageal sphincter is relaxed. In normal people, the pressure at the part of the esophageal area connected to the stomach (lower esophageal sphincter) is higher than the stomach pressure to prevent the gastric contents from refluxing into the esophagus. In contrast, during general anesthesia, the lower esophageal sphincter relaxes due to nerve inhibition, and the pressure zone disappears, which in turn triggers reflux.

Second, during general anesthesia, the swallowing reflex and cough reflex are inhibited. The former reflex prompts the swallowing of food from the pharynx into the stomach, and the latter reflex prevents foreign bodies in the larynx from entering the trachea. Under normal conditions, even if we experience reflux of stomach contents (vomiting), we can prevent them from entering the lungs (spitting, swallowing, coughing). But under general anesthesia both reflexes are suppressed and the risk can only be reduced by reducing the pitfalls (stomach contents).

Third, during anesthesia and surgery, there are many factors that can cause an increase in intragastric pressure. For example, some anesthetics themselves can cause an increase in intragastric pressure, and other conditions such as mask buckling, surgical operations, and forceful coughing when the patient awakens can lead to pressure higher than that of the lower esophageal sphincter, which in turn leads to reflux.

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Therefore, when under general anesthesia, patients undergoing non-emergency surgery require preoperative water fasting. However, the water fasting requirements are different for each individual and are related to age and physical condition, so let's wait for the next question to come up with more details in this regard.

People who have had surgery should know that the day before the surgery, the doctor will explain to the patient the precautions for the surgery. For example, they will often say which bed xxx is going to have an operation tomorrow, and that they can't eat or drink water after 12:00 pm.

Some patients may have the misunderstanding that it is okay not to eat or drink, and that eating something else will not affect the operation. I encountered a patient, to the ward to pick up the patient when the doctor asked: did not eat, did not drink water, right. The patient answered sharply and said: "No." The doctor asked again: "What else can I eat that won't affect my surgery? The doctor also asked: other did not eat it. The patient replied: just half an hour ago ate a small apple. The doctor was helpless and told the patient to postpone the operation.

After anesthesia the patient feels no pain, the muscles are in a state of relaxation and normal physiological reflexes disappear. There are many kinds of anesthesia, anesthesia will have risks, the smooth operation can not be carried out without the cooperation of the patient.

After the patient is anesthetized, the muscles are in a state of relaxation, and the normal physiological reflexes will disappear. If the patient is in a state of "full stomach", the stomach contents may reflux and be aspirated, leading to pneumonia. When vomiting occurs, the stomach contents may block the airway and lead to asphyxiation and death. Therefore, surgical patients must pay attention to the doctor's instructions.

The duration of fasting and abstinence from food and drink varies from patient to patient.

So in order to ensure the safety of anesthesia surgical patients should routinely empty the stomach, strict implementation of fasting and drinking requirements. 1. adult anesthesia: anesthesia should be fasted for at least 6 hours before anesthesia, fasting for 4 hours to ensure that gastric emptying 2. pediatric anesthesia: pediatric fasting, fasting and drinking can be shorter than the adult, fasting for 4-8 hours before surgery, fasting for 2-3 hours. 4. acute abdominal, severe trauma patients, fasting is not enough or unknown eating time Before anesthesia, gastric tube should be left in place to reduce gastric contents appropriately, and antiemetic drugs should be used before surgery to prepare suction device and transparent mask to be ready for aspiration at any time.

Be sure to do a good job of preoperative visits to surgical patients, explaining to patients and their families (especially the families of pediatric patients) the importance of fasting and abstaining from food and drink, to ensure the smooth progress of the operation.

Respondent: Xiaoyu Zhang, M.S., M.A.

Why can't I eat or drink before having surgery? This is a question that interests many members of the general public. In fact, it is not difficult to understand, and today Dr. Zhang will tell you about this question. I hope it will be helpful to you.

The main reason why we can't eat or drink before having the surgery is because under normal circumstances, the body has a choking nerve reflex and a swallowing nerve reflex, which is normal, and the esophageal sphincter functions normally, so the stomach contents usually don't reach up to our esophagus and oropharynx, and vomiting rarely occurs. Even if vomiting occurs, we will spit out the contents of the stomach or suppress them, thus ensuring that the stomach contents will not be accidentally inhaled into the lungs, and of course we are safe at that point.

However, if after anesthesia, our esophageal sphincter becomes relaxed and does not function normally as it does when we are awake, the stomach contents will easily regurgitate upward and even reach our oropharynx, and what's more, our nerve reflexes are inhibited, and at this time it is very likely that we will inhale the stomach contents into our lungs, which will result in aspiration and lead to aspiration pneumonia, or it will obstruct our airways, which is This can be fatal. This is also very harmful to the patient, and even life-threatening, therefore, we will make sure that the patient is prohibited from eating and drinking before the operation.

Through Dr. Zhang's speech above, do you understand why you can't eat before the surgery? In fact, in time you do not eat, the doctor will also give you intravenous infusion of some energy to ensure that the normal physiological functions of the patient's body.

This is a good question and one that many patients find confusing.

Why are you not allowed to eat before anesthesia for surgery? Similar questions include, why do I have to fast before a tracheoscopy, gastroscopy, or colonoscopy?

Physiologically, the lower esophageal sphincter where the esophagus connects to the stomach can play the role of a "gate" to prevent the stomach from refluxing food and stomach acid into the esophagus and mouth.

Under anesthesia, the lower esophageal sphincter is anesthetized and in a state of relaxation, the role of this "gate" disappeared, and if there is food in the stomach, it is possible to return to the esophagus and the oral cavity, and under anesthesia some of the human body's normal physiological functions (the swallowing reflex and the cough reflex) are inhibited, the reflex disappeared, and the stomach contents (including food) may flow back into the mouth, vomiting accidentally inhaled into the trachea, resulting in aspiration pneumonia. Under anesthesia, some normal physiological functions of the human body (swallowing reflex and coughing reflex) are suppressed, and the reflux to the mouth of the gastric contents (including food) may be refluxed and vomited into the trachea, resulting in aspiration pneumonia, which may lead to oxygen deprivation, suffocation or even death. At the same time, some anesthetics may also cause the increase of intragastric pressure, mask pressure oxygenation during anesthesia induction, patient's coughing, etc., which may cause the increase of intragastric pressure and lead to the reflux of gastric contents.

Aspiration in clinical anesthesia is a very serious complication, but also anesthesiologists focus on the problem, therefore, in addition to simple local infiltration anesthesia, all other anesthesia should be fasted before surgery, which is also the anesthesiologists preoperative follow-up of the patient's focus on the issue of explanation, I have many years of anesthesia work in the follow-up of the patient one day before the operation, must be explained to explain the problem is, fasting and drinking, adult General anesthesia at least 8 hours before the start of fasting, pediatric preoperative fasting at least 8 hours, but breastfeeding infants can be fed glucose water 4 hours before the operation. ASA pediatric fasting time less than 36 months fasting 2 hours for water, 4 hours for drinks, and 6 hours for food including milk.

The importance of fasting and abstinence from food and drink must be clearly explained to patients and their families in order to gain their cooperation. I have met patients who secretly drank water and milk or even ate cookies due to thirst or hunger, so the operation was postponed until they had fasted for a sufficient period of time before they were allowed to re-enter the operating room for surgery and anesthesia.

There is one situation where anesthesia is necessary even in the presence of food (full stomach), i.e., emergency, salvage anesthesia for emergency surgery, and this is one of the more difficult dilemmas that anesthesiologists sometimes encounter because of the higher probability and risk of aspiration in patients with full stomachs, and the harm that aspiration can cause to the patient is often fatal. The principle of anesthesia management to minimize and deal with the risk of perioperative reflux aspiration, all considerations are based on the safety of the patient with a full stomach.

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Thank you!

Those of you who have ever had surgery, especially general anesthesia surgery, should know that before the surgery, the doctor will instruct you to start fasting on food and water from a few points and hold back! Don't eat even if you're hungry, and you can't drink water!

Why is that? It's the doctor deliberately tossing people! Re! It's the doctor trying to protect you! To make it as safe as possible for you to go up to the operating table and be able to come down again safely!

Performing a general anesthesia procedure in a state where there is a lot of food inside your stomach can pose a risk of aspiration. When you are anesthetized and asleep, there is no way to control your body. At this time, because of the drug, the lower esophageal sphincter will relax, if the stomach is not emptied inside, there is reflux, resulting in aspiration pneumonia, or even vomiting, vomit blocking the airway, all of these can kill people!

Therefore, in order to try to avoid the occurrence of this risk before the operation will try to let the stomach leave time to empty, in advance, nothing to eat or drink, we must follow the doctor's advice to follow the doctor's advice to follow the doctor's advice ah!

There was once a classic joke, the doctor told the patient not to eat or drink before the operation, the results of the patient is very obedient, the operation told the doctor, I did not eat or drink, I ate two pieces of cake and drank a cup of milk tea!

Before anesthesia for each surgery, an anesthesiologist conducts a preoperative visit with the patient.

Patients will also be told that they need to abstain from food and drink before the operation, however, there are many patients who cannot understand this.

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Why can't I eat or drink before having surgery?

Deep sedation as well as general anesthesia drugs can attenuate the protective choking and swallowing reflexes or even make them disappear.

Relaxation of the esophageal sphincter is highly susceptible to reflux of gastric contents into the oropharynx.

Once a patient undergoing surgical treatment or examination hasReflux of gastric contentsInhalation into the respiratory tract can causerespiratory tract obstruction和aspiration pneumonia。

In severe cases, it can lead toPatient asphyxiationand difficult to treat.Extremely high mortality rate。

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Are the preoperative fasting requirements the same for everyone?

The answer, of course, is no.

with regards toPatients and children without abnormalities of gastrointestinal motilityThe amount that can be consumed should be less than or equal to 5 ml/kg (or less than or equal to 400 ml in total);

Newborns and infantsBreast milk was prohibited 4 hours before anesthesia and formula or cow's milk was prohibited 6 hours before anesthesia;

Starchy solid foods were prohibited 6 hours before anesthesia; fat and meat solid foods were prohibited 8 hours before anesthesia.

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Patients with the following conditions require extended fasting:

1. Patients with severe trauma, fasting until the time of injury is less than 6 hours;

2. Patients with gastrointestinal obstruction;

3, difficult airway patients, obese patients, patients with craniocerebral injury, intracranial hypertension and coma and other central nervous system diseases.

So.It is important to follow your doctor's advice to rationalize your preoperative fasting time to avoid intraoperative or postoperative complications.

Hunan Medical Chat Contributed by Zheng Fangkun, Department of Anesthesiology, Hunan Provincial Hospital of Chinese Medicine Research Institute

Xiong Zhaogang, Xi'an Chest Hospital

I'm sure many of you are aware that during the patient talk prior to surgery, the anesthesiologist will deliberately emphasize the need not to eat, but not all surgeries are off limits. The requirements for fasting are different for different types of anesthesia.

Anesthetic surgery is divided into local anesthesia and general anesthesia. Local anesthesia refers to the patient's conscious state, the local anesthetic applied to the local body, so that a part of the body's sensory nerve conduction function is temporarily blocked, motor nerve conduction remains intact or at the same time there is a varying degree of blocked state, the surface of the body of a number of small surgeries are to take local anesthesia, such as thoracic puncture, lumbar puncture and other surgical procedures of anesthesia. General anesthesia refers to the temporary suppression of the central nervous system produced by general anesthetics, with clinical manifestations of loss of consciousness, loss of generalized pain sensation, amnesia, reflex inhibition, and skeletal muscle relaxation, and general anesthesia is generally adopted for major surgeries, such as thoracoscopic surgery, laparoscopic surgery, and so on.

For local anesthesia, there is no risk of reflux or aspiration because consciousness is not affected, and eating and drinking are generally not prohibited, as in the case of thoracentesis or abdominal puncture. However, local anesthesia procedures via the digestive and respiratory tracts should not be eaten before surgery.

For general anesthesia, strict dietary abstinence is required, this is because emptying the stomach contents can avoid reflux and vomiting of gastric contents into the trachea for aspiration. Reducing gastric contents reduces the risk of reflux and aspiration during anesthesia, which, if they occur, may burn the airway or even cause aspiration pneumonia.

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"So-and-so, you're going to have surgery tomorrow, and you can't even eat anything after 10:00 tonight, not even water!" This is what clinicians often say to their patients the night before surgery, and most patients are just so baffled that they may even think to themselves that they are about to have surgery and should have something to eat or drink to replenish their energy. This is actually not the case.

Why can't I eat before surgery?

In clinical practice, there is a perioperative period before a patient undergoes surgery, mainly for the patient to do preoperative preparation and promote postoperative repair. One of the perioperative treatments is gastrointestinal preparation, which generally refers to fasting from 8 to 12 hours before surgery, and prohibiting drinking water from 4 hours before surgery. The main reason is that anesthesia uses muscarinic medication, and if the stomach is not emptied, it may cause gastric reflux, and after anesthesia, the patient is in a kind of unconsciousness, and it is very likely that asphyxia or aspiration pneumonia will occur during anesthesia and surgery, which is very critical. This is very critical. In some surgeries, gastrointestinal decompression is even done before surgery to meet the needs of surgery.

Patients involved in gastrointestinal surgery are usually started on a liquid diet one to two days before surgery, and those with pyloric obstruction require preoperative gastric lavage. For general surgery, a soap and water enema is done one day before surgery, if appropriate. For colon or rectal surgery, a cleansing enema or colonic enema, as appropriate, is given one day before surgery and early in the morning on the day of surgery, and oral intestinal antibacterial medications are started two to three days before surgery to minimize the chance of postoperative infection.

Therefore, preoperative fasting and abstinence from food and drink are for the safety of the patients, rather than the doctor deliberately not allowing them to eat. For general anesthesia, it is necessary to strictly prohibit food and drink, because once choking and aspiration pneumonia occur, the patient's life will be endangered. As doctors, we need to let the patient fall asleep quietly and have a smooth operation, as well as let the patient wake up safely.

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The purpose of fasting before anesthesia is to make the patient's gastric acid secretion lower and gastric pH higher, so as to reduce the risk of vomiting, reflux and inhalation into the lungs, which can lead to chemical damage. The drugs used during anesthesia, the operation, and the operation of the surgeon, especially the gastrointestinal surgery, can lead to the reflux of gastric contents during the operation, and if inhaled into the lungs, it will cause chemical damage, and the higher the acidity, the more serious the damage is, and even have the possibility of death. Therefore, patients should not eat or drink any water before the surgery. Emergency surgery due to the critical nature of the disease can not be required to be fasting, but must inform the anesthesiologist whether the anesthesiologist ate, drank, in order to allow the anesthesiologist to prepare for the prevention of aspiration.

The main reason is that anesthesia will use muscle relaxants, if the stomach is not emptied, it may lead to reflux of the contents, and if choked into the lungs, aspiration can lead to aspiration pneumonia, serious life-threatening!